The present invention relates to an oxidizer supply control system for controlling the flow of oxidizer into a combustion chamber of a gas turbine engine.
Gas turbine engines are equipped with oxidizer supply systems to supply oxidizer to the combustion chamber. In known fashion, the oxidizer is mixed with a fuel and burned in the combustion chamber. The oxidizer supply system may include a plurality of variable diaphragms to regulate the amount of oxidizer fed into the combustion chamber. These known diaphragms may have a generally cylindrical member defining a plurality of openings through which the oxidizer may pass into the combustion chamber. In known fashion, a sleeve is rotatably attached to an outer surface of the annular member, the sleeve also defining a plurality of openings. Rotation of the sleeve with respect to the cylindrical diaphragm member may place the openings of the sleeve in alignment with those of the diaphragm member to maximize the oxidizer flow into the combustion chamber. By rotating the sleeve member, the alignment of the respective openings may be changed so as to control the oxidizer flow through the diaphragm member.
Such known systems have control devices to control the rotation of the sleeve relative to the diaphragm. A known system shown in European Patent 0 455 559 control adjacent pairs of diaphragms by using a mechanically actuated rod connected to the sleeves of the adjacent pairs. A flexible drive shaft rotates cam elements of a plurality of such actuators to move the piston rods so as to rotate the sleeves and control the flow of oxidizer into the combustion chamber.
While this known system has proven reasonably effective, the mechanical drive system is complex, consisting of many precision components and requires substantial maintenance and repair to maintain its effectiveness.